-LRB- CNN -RRB- -- Manny Pacquiao 's career will be defined by Floyd Mayweather , even if the Filipino ca n't give boxing the fight it has long been clamoring to see .

That 's the view of Sports Illustrated 's boxing correspondent , Bryan Armen Graham .

He says he is optimistic that Pacquiao and Mayweather can finally reach a deal to settle who is the best pound-for-pound fighter in the sport .

Pacquiao 's next fight is in May next year while Mayweather is due in court next month to answer charges of domestic violence . Should he retain his liberty , Graham thinks a showdown in December 2011 is a possibility .

And according to Graham , the danger for eight-division world champion Pacquiao is that his legacy will be affected just as much by a failure to meet Mayweather in the ring than if the fight goes ahead .

He told CNN : `` If Manny gets through his next fight scheduled for May 7 and if Floyd resolves his problems I think there is actually a good chance . I 'm as optimistic as I have been in long time for that fight to come off late in the year , maybe December .

`` But the truth is there are a lot of theories about Floyd maybe waiting for Pacquiao to be past his prime , like Sugar Ray Leonard did with Marvin Hagler in the eighties .

`` Manny Pacquiao , I think he is a once in a generation type talent . I know there are people calling him greatest of all time and you always kind of rush to judge these things when you see someone so spectacular in their prime .

`` Its really unprecedented what he is doing but I think we are probably going to have to wait until all is said and done until we really make judgments on his career .

`` One thing for sure though is if the Floyd Mayweather fight does n't happen he -LSB- Pacquiao -RSB- might be defined just as much for not having that fight . ''

Pacquiao , who is a congressman in the Philippines , is due to announce who his next opponent will be at his 32nd birthday celebrations on Friday with Shane Mosley , Juan Manuel Marquez and Andre Berto in the frame .

Graham explained : `` There is Shane Mosley , the former WBA welterweight champion , Juan Manuel Marquez , the current WBO lightweight champion , and a dark horse candidate is Andre Berto , the former Olympian , who is undefeated but has not really fought anybody of note and has the lightest resume of the three .

'' -LSB- Mosley -RSB- is the best known but at the same time he is also coming off two really bad performances . He lost 11 of 12 rounds against Floyd Mayweather in May and he had a very , very listless controversial draw -LSB- with Sergio Mora -RSB- in September .

`` He is 39-years-old and he probably does n't deserve a shot against the pound-for-pound champion , but deserves seldom has anything to do with it in boxing . ''

Pacquiao made history by becoming the first fighter to claim titles in eight weight divisions after his victory over Antonio Margarito secured the vacant WBC super-welterweight belt .

According to reports in the Philippines , Pacquiao is currently ironing out a query over his taxes arising from fights in 2009 . He recently moved his next fight from April to May due to his political responsibilities in the country .

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Floyd Mayweather will define Manny Pacquiao 's career even if fight ca n't be made , says pundit

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Sports Illustrated 's boxing editor Bryan Graham Armen optimistic fight will happen

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Pacquiao poised to announce his next opponent on Friday

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Mayweather due in court in January to answer domestic violence charges